Why Is My Dog So Itchy? Common Causes of Itchy Skin in Dogs
Seasonal allergies in Ontario can make fall especially challenging for some dogs. Here’s how to tell whether allergies, fleas, food, infection or something else may be behind your dog’s itching.
If your dog suddenly seems to be scratching, licking, chewing, or rubbing themselves more than usual, you’re not alone. Itchy dogs are one of the most common reasons pet owners seek veterinary care, and September can be an especially challenging time for dogs with seasonal allergies in Ontario.
Ragweed, grass and other environmental allergens can trigger itchy skin, while fleas, food allergies, infections and other skin conditions can cause very similar symptoms.
So how do you know what’s causing your dog’s itch — and what can you do about it?
Why are dogs so itchy in the fall?
Ontario’s allergy season can extend from spring into fall, with different allergens becoming more prominent throughout the year.
By late summer and early fall, ragweed pollen is an important environmental allergen. Dogs can also react to grasses, molds, dust mites and other environmental allergens. Some dogs have seasonal allergies, while others experience symptoms throughout the year.
If your dog’s itching seems to get worse every August or September and then improves during the winter, a seasonal environmental allergy may be part of the picture. But seasonality alone doesn’t prove that allergies are the cause.
What are the most common causes of an itchy dog?
There are several possibilities, and sometimes more than one is happening at the same time.
1. Environmental allergies
Environmental allergies, sometimes called atopic dermatitis or atopy, occur when a dog’s immune system overreacts to substances in the environment.
Common triggers include:
Tree pollen
Grass pollen
Weed pollen, including ragweed
Mold and mildew
Dust mites
Dogs with environmental allergies often lick or chew their paws, scratch their ears and face, or develop itchy skin around their armpits, groin and belly.
Environmental allergies can be seasonal or year-round, depending on what your dog is reacting to.
2. Flea allergy
Don’t assume that an itchy dog can’t have a flea allergy just because you don’t see fleas.
Some dogs are extremely sensitive to flea saliva, and a single flea bite can trigger a significant allergic reaction in a susceptible dog.
Flea allergy dermatitis often causes intense itching, particularly around the back end and base of the tail.
This is one reason consistent flea prevention is so important — even for dogs that don’t spend much time outdoors.
3. Food allergies
Food allergies are possible, but they’re often misunderstood. Dogs can develop allergies to ingredients they’ve eaten for a long time. Common dietary allergens include certain animal proteins, although almost any dietary protein can potentially be involved.
Food allergies can cause itching, but some dogs also have gastrointestinal signs such as vomiting, diarrhea, soft stool or excessive gas.
The only reliable way to diagnose a food allergy is generally through a strict veterinary-directed elimination diet trial followed by a controlled food challenge. Simply switching from one commercial food to another for a week or two usually isn’t enough to determine whether your dog has a food allergy.
4. Skin or ear infections
Allergies aren’t always the whole problem. Dogs with allergies can damage their skin by scratching and chewing, which can allow bacteria or yeast to multiply. This can create a cycle:
Allergy → itching → scratching/licking → damaged skin → infection → even more itching
Signs of a secondary infection can include:
Red or inflamed skin
A strong or unusual odor
Greasy or flaky skin
Crusts or scabs
Hair loss
Hot spots
Recurrent ear infections
Head shaking
If your dog is itchy enough to create wounds or the skin is becoming raw, it’s time to have them examined.
5. Parasites and other skin conditions
Fleas aren’t the only parasites that can cause itching. Certain mites can cause significant skin irritation, and other conditions — including fungal infections and some less common skin diseases — can look similar to allergies.
That’s why treating an itchy dog isn’t always as simple as choosing an allergy medication.
Why are my dog’s paws so itchy?
This is one of the most common questions we hear.
Dogs with environmental allergies frequently lick and chew their feet. Pollen and other environmental allergens can come into contact with the paws, and the skin between the toes can become inflamed.
But itchy paws don’t automatically mean allergies.
Other possibilities include:
Yeast or bacterial infections
Foreign material between the toes
Contact irritation
Parasites
Injury
Other inflammatory skin conditions
If your dog is constantly licking their feet, particularly if the paws are red, swollen, smelly or losing hair, a veterinary examination can help determine what’s actually happening.
Does washing my dog’s paws after a walk help?
It can.
Wiping or rinsing your dog’s paws after spending time outside can help remove pollen and other environmental material before your dog has a chance to lick it off.
A simple rinse with water may be all that’s needed for some dogs. Your veterinarian may also recommend a specific medicated or hypoallergenic product depending on your dog’s skin condition.
If you’re washing your dog’s paws frequently, make sure you’re not using harsh soaps or products that could further irritate the skin. And don’t forget to dry the paws thoroughly.
What about Epsom salt foot baths?
This is a question that comes up frequently online.
An Epsom salt soak may feel soothing to some dogs, but it isn’t a treatment for the underlying cause of allergic skin disease.
If your dog has significant inflammation, open sores, or a suspected infection, home remedies may not be enough — and some products can actually make irritated skin worse.
If your dog is licking or chewing their feet enough to create wounds, it’s better to have the underlying problem assessed rather than relying on increasingly frequent foot baths.
Would dog boots help with seasonal allergies?
Possibly — but they’re not a solution for every dog.
Boots can reduce direct contact between your dog’s paws and grass, pollen or other outdoor irritants. Some dogs tolerate them well, while others find them uncomfortable or simply won’t keep them on.
If you use boots, make sure they fit properly and that your dog’s paws are kept clean and dry.
For many dogs, a quick paw rinse after outdoor activities may be a simpler and more practical option.
Can I give my dog Benadryl or another antihistamine?
This is another common question — and it’s one where you should be cautious about taking advice from the internet.
Some antihistamines, including diphenhydramine (Benadryl), are used in dogs under veterinary guidance. However, the appropriate medication and dose depend on the individual dog, and some products contain additional ingredients that may not be appropriate for pets.
Antihistamines also don’t work particularly well for every dog with allergic skin disease.
If your dog is itchy enough that you’re considering medication, talk with your veterinarian before starting a new drug or changing the dose.
What about Zyrtec?
Cetirizine is another antihistamine sometimes used in dogs, but just because a medication is available over the counter for people doesn’t mean it is appropriate for every pet.
Your veterinarian can help determine whether an antihistamine is likely to help your dog and whether there are safer or more effective options for their particular situation.
What about Apoquel or Cytopoint?
These are two treatments that many owners hear about when researching itchy dogs.
Apoquel (oclacitinib) is an oral medication that targets specific pathways involved in allergic itch.
Cytopoint (lokivetmab) is an injectable treatment that targets a key protein involved in the itch signal.
Both can be useful for appropriately selected dogs, but neither should be thought of as a universal solution for every itchy dog.
The important first step is determining why your dog is itchy and whether there are infections, parasites or other conditions that also need to be addressed.
Your veterinarian can discuss which treatment options make sense for your dog.
What if my dog’s skin is breaking?
This is important.
If your dog is scratching or chewing enough to create raw skin, bleeding, scabs or small wounds, don’t simply assume it’s “just allergies.”
Damaged skin can become infected, creating another source of inflammation and itching.
One recent discussion among dog owners about seasonal allergies highlighted exactly this issue: once persistent paw chewing creates small wounds, the problem can become more complicated than simply controlling the original itch.
If your dog’s skin is broken, worsening, painful, oozing or developing an odor, it’s a good idea to have them examined.
How does a veterinarian figure out what is causing the itching?
Diagnosing an itchy dog is often a process rather than a single test.
Your veterinarian will typically want to know:
When did the itching begin?
Is it seasonal?
Where is your dog itching?
How severe is the itching?
Is your dog on consistent flea and tick prevention?
Has anything changed at home?
What food and treats does your dog receive?
Has your dog had ear infections or skin infections before?
What treatments have you already tried?
Did those treatments help?
Your veterinarian may also recommend diagnostic testing such as:
Flea combing
Skin scrapings
Skin cytology
Ear cytology
Fungal testing when indicated
A carefully controlled food trial
Allergy testing in selected cases
Importantly, there isn’t a single blood test that simply tells you whether your dog has allergies.
Environmental allergy testing is generally used after other causes have been considered and is particularly useful when allergy-specific immunotherapy is being considered.
What can I do at home to help an itchy dog?
There are several simple things that may help reduce exposure to environmental allergens:
After walks
Wipe or rinse your dog’s paws and, if appropriate, their coat after outdoor activities.
Keep bedding clean
Wash your dog’s bedding regularly using a fragrance-free detergent if possible.
Keep your home clean
Regular vacuuming and dusting can help reduce indoor allergens such as dust and dust mites.
Stay consistent with parasite prevention
Flea allergy can cause significant itching, even when you don’t see fleas.
Avoid over-bathing
Bathing can help remove allergens from the skin, but excessive bathing or inappropriate shampoos can dry and irritate the skin.
If your veterinarian has recommended a specific shampoo or topical treatment, follow their instructions carefully.
When should I take my itchy dog to the veterinarian?
A little occasional scratching isn’t necessarily cause for alarm.
But you should consider booking an appointment if your dog:
Is scratching or licking much more than normal
Is waking up or losing sleep because of itching
Has red or inflamed skin
Is losing hair
Has recurrent ear infections
Is constantly licking their paws
Has hot spots
Has scabs or open wounds
Has a skin odour
Is shaking their head frequently
Has itching that keeps coming back
And if your dog is experiencing severe itching, facial swelling, difficulty breathing, vomiting, collapse or other signs of a serious allergic reaction, seek veterinary care promptly.
The good news: itchy dogs can often feel much better
Allergies can be frustrating because there isn’t always a single permanent cure. The goal is to identify the factors contributing to your dog’s itching and create a management plan that keeps them comfortable.
For some dogs, that might mean controlling fleas and using regular topical therapy. Others may benefit from dietary management, prescription medications, allergy immunotherapy, or a combination of treatments.
The right approach depends on the individual dog.
Is your dog suddenly much itchier this fall?
If your dog has started scratching, licking or chewing more than usual, don’t assume it’s simply seasonal allergies.
At Bridge Street Veterinary Hospital, we can help determine what’s causing the itch and develop a treatment plan tailored to your pet.
Your dog shouldn’t have to spend the season scratching.
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